Pescatarian Diet Archives - Health Tips From The Professor

Which Diets Are Heart Healthy?

September 26, 2023 by Dr. Steve Chaney

What Does A Heart Healthy Diet Look Like?

Author: Dr. Stephen Chaney

Heart disease is a big deal. According to the CDC, “Heart disease is the leading cause of death for men, women, and people of most racial and ethnic groups in the United States. One person dies every 33 seconds in the United States from cardiovascular disease. About 695,000 people in the United States died from heart disease in 2021 – that’s 1 in every 5 deaths”.

This doesn’t have to happen. According to the Cleveland Clinic, “90 percent of heart disease is preventable through healthier diet, regular exercise, and not smoking”. For this issue of “Health Tips From the Professor”, I will focus on the role of diet on heart health.

The problem is many Americans are confused. They don’t know what a heart-healthy diet is. There is so much conflicting information on the internet.

Fortunately, the American Heart Association has stepped in to clear up the confusion.

In 2021 they reviewed hundreds of clinical studies and published “Evidence-Based Dietary Guidance to Promote Cardiovascular Health”.

And recently they have published a comprehensive review (CD Gardner et al, Circulation, 147: 1715-1730, 2023) of how well popular diets align with their 2021 dietary guidelines.

I will cover both publications below. But first I want to address why Americans are so confused about which diets reduce heart disease risk.

Why Are Americans Confused About Diet And Heart Disease Risk?

I should start by addressing the “elephant in the room”.

As I discussed in last week’s “Health Tips From the Professor” article, Big Food Inc has seduced us. They have developed an unending supply of highly processed foods that are cheap, convenient, easy to prepare, and fulfill all our cravings. These foods are not heart-healthy, but they make up 73% of our food supply.

The Institute of Medicine, the scientific body that sets dietary standards, states that a wide range of macronutrient intakes are consistent with healthy diets. Specifically, they recommend carbohydrate intake at 45% to 65%, fat intake at 20% to 35%, and protein intake at 10% to 35% of total calories. (Of course, they are referring to healthy carbohydrates, fats, and proteins.)

The authors of this article pointed to several reasons why Americans have been misled about heart-healthy diets.

Many of the most popular diets fall outside of the “Acceptable Macronutrient Range”.

Many popular diets exclude heart-healthy food groups.

And, the words of the authors,

“Further contributing to consumer misunderstanding is the proliferation of diet books, [and] blogs [by] clinicians with limited understanding of what the dietary patterns entail and the evidence base for promoting cardiometabolic health.” I call these the Dr. Strangeloves of our world.

What Does A Heart Healthy Diet Look Like?

Let me start by sharing the American Heart Association’s 10 “Evidence-Based Dietary Guidelines to Promote Cardiovascular Health.

#1: Adjust energy intake and expenditure to achieve and maintain a healthy body weight
#2: Eat plenty of vegetables and fruits; choose a wide variety
#3: Choose foods made mostly with whole grains rather than refined grains
#4: Choose healthy sources of protein
	Mostly from plants (beans, other legumes, and nuts)
	Fish and seafood
	Low-fat or fat-free dairy products instead of full-fat dairy products
	If meat or poultry are desired, choose lean cuts and avoid processed forms
#5. Use liquid plant oils (olive, safflower, corn) rather than animal fats (butter and lard) and tropical oils (coconut and palm kernel)
#6. Use minimally processed foods instead of highly processed foods
#7: Minimize intake of beverages and foods with added sugars
#8: Choose and prepare foods with little or no salt
#9: If you do not drink alcohol, do not start; if you choose to drink alcohol, limit intake
#10: Adhere to this guidance regardless of where food is prepared or consumed

Here are my comments on these guidelines:

If you have been reading my “Health Tips From the Professor” blog for a while, you probably realize that these aren’t just guidelines to promote heart health. These guidelines also reduce the risk of diabetes, cancer, inflammatory diseases, and much more.

If you have read my post on coconut oil, you will know that I have a minor disagreement with the AHA recommendation to avoid it. There is no long-term evidence that coconut oil is bad for the heart. But there is also no long-term evidence that it is good for the heart. My recommendation is to use it sparingly.

And you probably know there has been considerable discussion recently about whether full fat dairy is actually bad for the heart. In my most recent review of the topic, I concluded that if full fat dairy is heart healthy, it is only in the context of a primarily plant-based diet and may only be true for fermented dairy foods like unpasteurized yogurt and kefir.

Finally, guideline 10 may need some translation. Basically, this guideline is just asking how easy it is to follow the diet when you are away from home.

Which Diets Are Heart Healthy?

In evaluating how well diets adhered to the American Heart Association guidelines the authors ignored item 1 (energy intake) because most of the diets they evaluated did not provide any guidelines on how many calories should be consumed.

Each diet was given a score between 0 (Fail) and 1 (A+) for each of the other 9 guidelines by a panel of experts. The points for all 9 guidelines were added up, giving each diet a rating of 0 (worst) to 9 (best). Finally, a score of 9 was assigned 100%, so each diet could be given a percentage score for adherence to heart-healthy guidelines.

Here are the results:

Tier 1 diets (the most heart healthy diets) received scores of 86% to 100%. Going from highest (100%) to lowest (86%), these diets were:

DASH, Nordic, Mediterranean, Pescetarian (vegetarian diets that allow fish), and Ovo-Lacto Vegetarian (vegetarian diets that allow dairy, eggs, or both).

You will notice that these are all primarily plant-based diets.

Tier 2 diets were Vegan and other low-fat diets (TLC, Volumetrics). They both received scores of 78%.

The Vegan diet received 0 points for category 10 (ease of following the diet when eating out). It was also downgraded in category 7 for not having clear guidance for the use of salt when preparing foods.

The other low-fat diets were downgraded in categories 7, 10, and 5 (use of tropical oils).

Tier 3 diets received scores of 64% to 72%. They included very-low fat diets (<10% fat, very strict vegan diets) and low-carb diets (Zone, South Beach, Low-Glycemic Index).

They received 0 points for category 10 and were downgraded for eliminating heart-healthy food groups (liquid plant oils for the very low-fat diets, and fruits, vegetables, whole grains, and plant proteins for the low-carb diets).

Tier 4 diets (the least heart healthy diets) were the Paleo diet with a score of 53% and very low-carb diets (Atkins and Ketogenic) with a score of 31%.

The Paleo diet received 0 points for categories 10, 3 (choose whole grains), and 5 (using liquid plant oils rather than animal fats or tropical oils). It was also downgraded for lack of healthy plant-based protein sources.

The very low-carb diets were the least heart healthy. They received 0 points for categories 2 (eat plenty of fruits and vegetables), 3 (choose whole grains), 3 (healthy protein sources), 5 (use liquid plant oils instead of animal fats), 7 (minimize salt consumption), and 10 (ease of following the diet away from home).

The authors concluded, “Numerous [dietary] patterns [are] strongly aligned with 2021 American Heart Association Dietary Guidance (ie, Mediterranean, DASH, pescetarian, vegetarian) [and] can be adopted to reflect personal and cultural preferences and budgetary constraints.

Thus, optimal cardiovascular health would be best supported by developing a food environment that supports adherence to these patterns wherever food is prepared or consumed.”

Given our current food environment that last statement is wildly optimistic. But at least you have the information needed to make the best food choices for you and your family

The Bottom Line

In 2021 the American Heart Association published 10 guidelines for evaluating heart-healthy diets. A recent study looked at how well popular diets adhered to those guidelines. The authors separated the diets into four categories (tiers) based on how heart-healthy they were. The results were not surprising:

Tier 1 diets (the most heart healthy diets) were DASH, Nordic, Mediterranean, Pescetarian (vegetarian diets that allow fish), and Ovo-Lacto Vegetarian (vegetarian diets that allow dairy, eggs, or both).

Tier 2 diets were Vegan and other low-fat diets (TLC, Volumetrics).

Tier 3 diets included very-low fat diets (<10% fat, very strict vegan diets) and low-carb diets (Zone, South Beach, Low-Glycemic Index).

Tier 4 diets (the least heart healthy diets) were the Paleo diet and very low-carb diets (Atkins and Ketogenic).

Thus, optimal cardiovascular health would be best supported by developing a food environment that supports adherence to these patterns wherever food is prepared or consumed.”

Given our current food environment that last statement is wildly optimistic. But at least you have the information needed to make the best food choices for you and your family.

For more information on this study, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

____________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

Are Sustainable Diets Nutritionally Complete?

September 5, 2023 by Dr. Steve Chaney

How Do Sustainable Diets Compare With Meat-Based Diets?

Author: Dr. Stephen Chaney

In a previous issue of “Health Tips From the Professor” I have discussed a sustainable diet popularly known as the planetary diet. Here is a brief synopsis of that article:

The planetary diet came from an international commission called the “EAT-Lancet Commission on Healthy Diets From Sustainable Food Systems” (Bureaucrats and scientists love long names.)

They were commissioned to recommend a diet that was both healthy and sustainable (good for the environment) through the year 2050.

The commission reported that the methods of food production required to support our current diets:

- Occupy 40% of global land.

- Are responsible for 30% of global greenhouse gas production and 70% of freshwater use.

They further reported that:

- Reaching the Paris Agreement of limiting global warming…is not possible by only decarbonizing the global energy systems (In other words, we cannot limit global warming just by switching to electric cars and stoves.).

- Transformation to healthy diets from sustainable food systems is essential to achieving the Paris Agreement.”

- The world’s population is expected to reach 10 billion by 2050. The current system of food production is unsustainable.

The planetary diet they recommended is a primarily plant-based diet. But it is not any plant-based diet. It limits animal foods to an extent that approaches a vegan diet.

That raises two important questions:

Are sustainable diets like the planetary diet healthy? The answer to that question is a resounding, “Yes”. Numerous studies have shown that primarily plant-based diets are healthier than meat-based diets long term.

2) Are sustainable diets nutritionally complete? That is the question the authors of the current study (N Neufingerl and A Eilander, Nutrients, 14: 29, 2022) set out to answer.

How Was This Study Done?

The authors searched the literature and identified 147 high-quality articles published between 2000 and January 2020 that compared the nutritional adequacy of primarily plant-based diets or vegan diets with meat-based diets.

They excluded:

Intervention studies because the nutritionists designing those studies assured the nutritional adequacy of the plant-based diet used in the study.

Overly restrictive plant-based diets such as the raw food diet or macrobiotic diet.

Primarily plant-based diets for disease prevention like the Mediterranean or DASH diets because they were too unlike the planetary diet.

Studies with pregnant or lactating women, populations with specific diseases, and athletes.

They chose diets that measured intakes of energy (calories), protein, PUFA (polyunsaturated fats), total omega-3 fats, ALA, EPA, DHA, fiber, vitamins A, B1, B6, B12, niacin, folate, C, D, E, iron, zinc, calcium, iodine, magnesium, and phosphorous. [Note: Not all studies measured intakes of all the nutrients in this list.]

Their goal was to compare the nutritional adequacy of the diets, not the health of the diets. So, they did not report on the saturated fat, cholesterol, sugar, or percent processed food content of the diets.

How Do Sustainable Diets Compare With Meat-Based Diets?

The Study showed that:

Vegan diets:

Tended to be inadequate in EPA, DHA, vitamins B12, D, calcium, iodine, iron, and zinc.

Tended to have favorably high intakes of fiber, PUFA, ALA, vitamins B1, B6, C, E, folate, and magnesium.

Vegetarian diets:

Tended to be inadequate in fiber, EPA, DHA, vitamins B12, D, E, calcium, iodine, iron, and zinc.

Tended to have favorably high intakes of PUFA, ALA, vitamin C, folate, and magnesium.

Meat-eaters:

Tended to be inadequate in fiber, PUFA, ALA, vitamins D, E, folate, calcium, and magnesium.

Tended to have favorably high intakes of protein, niacin, vitamin B12, and zinc.

Other observations:

Pesco-vegetarians (vegetarians who include fish as a major protein source) had the highest intake EPA and DHA of any of the groups studied.

Both vegetarians and vegans had lower protein intake than meat-eaters, but their average protein intake was adequate.

Finally, there are two important reminders as you look at the data.

The data for each nutrient was based on average intake of that nutrient in the diet group. The authors did not report the percent of people consuming that diet who had inadequate intake.

The authors were comparing the nutritional completeness of each diet, not the effect of the diets on diseases like heart disease and diabetes. However, this comparison is important because nutritional inadequacies left untreated for a long period of time can have significant health consequences.

Are Sustainable Diets Nutritionally Complete?

The authors concluded “…there are dietary inadequacies in any [restrictive] diet.” This is no surprise.

With respect to sustainable plant-based diets, the authors said, “In people following self-selected plant-based diets, especially vegan diets, intake of certain nutrients is lower compared to meat-containing diets.”

So, the answer to the question, “Are sustainable diets nutritionally complete?”, is clearly, “No. They do not provide 100% of the essential nutrients you need.”

Long-term nutritional deficiencies can have serious health implications. So, what should you do about it?

The authors made the following recommendations, “As plant-based diets are generally better for health and the environment, public health strategies should facilitate the transition to a [more] balanced diet…through consumer education, food fortification, and possible supplementation.”

Let me comment on the three recommendations they listed:

Consumer education is a great idea, but it is usually drowned out by Big Food Inc’s advertising budgets and the misleading information provided by the Dr. Strangeloves of the world.

Food fortification is also a useful idea. After all, it has eliminated several deficiency diseases in the past. But it is hard to fortify fruits and vegetables. And eating more highly processed plant-food products is not the way to better health – even if they are fortified. Besides, I wouldn’t hold my breath waiting for the USDA to act.

That leaves responsible supplementation as the only viable option for anyone wanting to switch to a plant-based diet to save the planet. And if the environment is important to you, you will probably want to choose a supplement company that follows sustainable practices and is certified carbon neutral.

The Bottom Line

Primarily plant-based diets are healthier for you and healthier for the planet. But are they nutritionally complete?

A recent systemic review of 147 published studies was designed to answer that question. As you might suspect, the answer was a clear, “No”.

Vegan diets:

Tended to be inadequate in EPA, DHA, vitamins B12, D, calcium, iodine, iron, and zinc.

Vegetarian diets:

Tended to be inadequate in fiber, EPA, DHA, vitamins B12, D, E, calcium, iodine, iron, and zinc.

The authors concluded, “As plant-based diets are generally better for health and the environment, public health strategies should facilitate the transition to a balanced diet…through consumer education, food fortification, and possible supplementation.”

Let me comment on the three recommendations they listed:

Consumer education is a great idea, but it is usually drowned out by Big Food Inc’s advertising budgets and the misleading information provided by the Dr. Strangeloves of the world.

Food fortification is also a useful idea. But it is hard to fortify fruits and vegetables. And eating more highly processed plant-food products is not the way to better health – even if they are fortified.

That leaves responsible supplementation as the only viable option for anyone wanting to switch to a plant-based diet to save the planet. And if the environment is important to you, you will probably want to choose a supplement company that follows sustainable practices and is certified carbon neutral.

For more information on this study, and the science behind my summary of the study, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

___________________________________________________________________________

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

Will Plant Proteins Help You Live Longer?

April 13, 2021 by Dr. Steve Chaney

Is A Vegan Diet Healthiest?

Author: Dr. Stephen Chaney

Unless you are Rip Van Winkle and have been asleep for the past 40 years, you have probably heard that whole food, primarily plant-based diets are good for you.

They help you control your weight.

They reduce inflammation.

They reduce your risk of diabetes and heart disease.

They even reduce your risk of some cancers.

But do they help you live longer? If we take that question literally, the answer appears to be no. There is no “Fountain Of Youth”. There are no diets that extend our lives significantly.

However, what if you could reduce your risk of premature death? It would be tragic to have your life cut short by a heart attack or some other major disease. What if you could prevent that?

And what if you could live healthier longer? It would be equally tragic to spend your golden years debilitated by chronic diseases like heart disease, diabetes, or dementia. What if you could delay these diseases and live healthier longer?

The study I discuss this week (Y Sun, Journal of the American Heart Association, 10:e015553, 2021) looks at the effect of different dietary protein sources on premature death.

This study, like many others, suggests that primarily plant-based diets are healthier than meat-based diets. But what does this mean for you? Should you go completely meatless? Is a vegan diet healthier than other plant-based diets? I discuss what we know and what we do not know about the vegan diet compared to other plant-based diets.

How Was This Study Done?

The data for this study were drawn from the Women’s Health Initiative (WHI). The Women’s Health Initiative was designed to help identify strategies for preventing heart disease and other diseases in postmenopausal women. It enrolled 161,000 postmenopausal women from 40 sites across the US between 1993 and 1998 and followed them through 2017.

This study excluded women who had heart disease or cancer when they entered the WHI study and women who had incomplete data on either their diet or their use of postmenopausal hormone therapy. They were left with 102,521 women, age 50-79 at time of entry, who were followed for 18 years.

Each woman filed out an extensive dietary survey at the beginning of the study. There were 25,976 deaths during the study. The cause of death was determined by reviewing death certificates, medical records, autopsy reports or by linkage to the National Death Index.

The investigators asked whether women who ate more plant proteins were healthier than those who ate primarily meat protein. To answer this question, they correlated protein sources in the diet with all-cause mortality and deaths from various diseases.

The greatest difficulty with this type of study is that people who eat more plant protein tend to have a healthier diet and a healthier lifestyle. That makes it hard to separate out the benefits of eating plant proteins from benefits associated with other aspects of their diet and lifestyle. So, the authors corrected their data for every factor known to influence the risk of heart disease, diabetes, dementia, and premature death.

Specifically, the data were statistically corrected for age, race/ethnicity, socioeconomic status, hormone use, lifestyle (smoking status, physical activity, and alcohol intake), baseline health status (diabetes and/or high blood cholesterol), family history of heart attack/stroke, dietary factors (calorie intake, dietary fiber intake, whole grain consumption, fruit and vegetable consumption, sugar-sweetened beverage consumption, glycemic load (effect of foods in the diet on blood sugar), and percentage of saturated fats, polyunsaturated fats, monounsaturated fats, and trans fats), and weight (BMI).

In short, the authors corrected for every other factor that could influence disease risk and/or premature death. By doing so, they were able to focus on the effect of protein sources on disease risk and/or premature death.

Will Plant Proteins Help You Live Longer?

The investigators divided the study participants into quintiles with respect the kind and amount of protein they consumed.

For animal protein, the intake ranged from 4 ounces/day in the lowest quintile to 9 ounces a day in the highest quintile (For comparison, 3 ounces is roughly equivalent to the size of a deck of cards).

For plant protein, the intake ranged from 2 ounces/day in the lowest quintile to 3.5 ounces/day in the highest quintile.

When you combine plant and animal protein in these women’s diet, plant protein ranged from 18% of total protein intake in the lowest quintile to 48% of total protein intake in the highest quintile.

When women who had the highest intake for plant protein were compared with women who had the lowest intake of plant protein, the women with the highest plant protein intake had:

12% lower risk of premature death from heart disease.

21% lower risk of premature death from dementia.

9% lower risk of premature death from all causes.

There was an inverse relationship between the amount of plant protein in the diet and premature death. Specifically, every 3 ounces of animal protein that was replaced with 3 ounces of plant protein resulted in:

22% lower risk of premature death from heart disease.

19% lower risk of premature death from dementia.

14% lower risk of premature death from all causes.

The Effect Of Individual Animal Proteins On Mortality

The authors also looked at the effect of various animal proteins on premature death. For example:

Red Meat: Women with the highest consumption of red meat had:

14% higher risk of premature death from heart disease.

20% higher risk of premature death from dementia.

10% higher risk of premature death from all causes.

Eggs: Women with the highest consumption of eggs had:

24% higher risk of premature death from heart disease.

14% lower risk of premature death from dementia.

14% higher risk of premature death from all causes.

Dairy: Women with the highest consumption of dairy had:

11% higher risk of premature death from heart disease.

The authors concluded, “In this large prospective cohort study, we found that higher plant protein intake and substitution of animal protein with plant protein were associated with lower risk of all-cause mortality, cardiovascular mortality, and dementia mortality…Our findings support the need for consideration of protein sources, in addition to the amount of protein intake, in future dietary guidelines.”

Is A Vegan Diet Healthiest?

Years ago, as my brother-in-law was coming out of anesthesia at the end of quadruple bypass surgery, the first question he asked was, “Does this mean I need to eat tofu?” Obviously, nothing terrified him more than the thought of eating tofu the rest of his life. In the same vein, some of you are probably asking, “Does this mean I need to go vegan?”

The good news is that none of the women in this study were consuming a vegan diet. They were consuming a typical American diet with varying amounts of plant and animal protein. The group with the highest plant protein consumption were still getting 52% of their protein from animal sources.

This study shows that even people consuming a typical American diet can become healthier by simply swapping out some of the animal protein in their diet with plant protein.

However, you are probably thinking, “Plant protein is good for us, and a vegan diet is 100% plant protein. Does that mean a vegan diet is healthier than other plant-based diets?

The answer is………”Maybe”

If the linear relationship between plant protein consumption and risk of premature death could be extrapolated all the way to 100% plant protein, the answer would be obvious. Vegan diets would be healthier than other plant-based diets. But that extrapolation is an assumption. It might not be true.

For example, some recent studies suggest that completely eliminating meat, eggs, and dairy from your diet may slightly increase your risk of heart disease and stroke:

One recent study found that adding 1.4 ounces of fish/day to a primarily vegetarian diet decreases the risk of stroke by 20%.

Another study reported that adding one egg/day to a primarily vegetarian diet decreases the risk of heart disease by 12% and stroke by 10-26%.

These studies need to be confirmed, but they do suggest we need to be cautious about assuming that vegan diets are healthier than other primarily plant-based diets. This is why, when I recommend primarily plant-based diets, I include everything from vegan through semi-vegetarian, Mediterranean, and DASH.

They are all healthy diets. My advice is to choose the one that best fits your lifestyle and food preferences. And focus on whole foods, not processed foods.

The Bottom Line

A recent study asked whether women who ate more plant proteins were healthier than those who ate primarily meat protein. To answer this question, the investigators correlated protein sources in the diet with all-cause mortality and deaths from various diseases.

When women who had the highest intake for plant protein were compared with women who had the lowest intake of plant protein, the women with the highest plant protein intake had:

12% lower risk of premature death from heart disease.

21% lower risk of premature death from dementia.

9% lower risk of premature death from all causes.

22% lower risk of premature death from heart disease.

19% lower risk of premature death from dementia.

14% lower risk of premature death from all causes.

[Note: A 3-ounce serving is roughly equivalent to a deck of cards.]

I discuss the answer to that question in the article above.

For more details and a discussion about the vegan diet versus other primarily plant-based diets read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Which Foods Affect Stroke Risk?

March 24, 2020 by Dr. Steve Chaney

Why Is Diet And Stroke Risk So Confusing?

One day we are told vegetarian diets reduce our stroke risk. The next day we are told they increase stroke risk. It’s the same with red meat, dairy, and eggs. We keep getting mixed messages. It’s enough to make your head spin. Why is diet and stroke risk so confusing?

Part of the problem is that there are two distinct types of stroke. The technical names for them are ischemic stroke and hemorrhagic stroke.

An ischemic stroke occurs when an artery in the brain becomes blocked, shutting off blood flow and damaging part of the brain. This is usually caused by the gradual buildup of fatty deposits and cholesterol plaques in the arteries. When a blood clot forms and lodges in one of the narrowed arteries leading to the brain, an ischemic stroke occurs.

Ischemic strokes account for 87% of all strokes.

Ischemic strokes are associated with obesity, elevated cholesterol, diabetes, high blood pressure, and smoking.

A hemorrhagic stroke occurs when a weakened blood vessel bursts and bleeds into the surrounding region of the brain. Because our brains are surrounded by a protective skull, that blood has nowhere to go. Pressure from the buildup of blood damages brain cells in the vicinity of the bleed.

Hemorrhagic strokes account for only for only 15% of strokes but are responsible for 40% of stroke deaths.

The most common cause of a hemorrhagic stroke is the localized enlargement of a blood vessel due to chronic high blood pressure. This weakens the wall of the blood vessel, making it prone to rupturing.

Part of the confusion about diet and stroke risk is because many earlier studies did not distinguish between the two types of stroke.

If the studies just measured the incidence of stroke, the data were dominated by ischemic strokes (87% of strokes are ischemic).

However, if the studies focused on stroke deaths, hemorrhagic stroke made a larger contribution to the data set (40% of stroke deaths are hemorrhagic).

Fortunately, recent studies have started to focus on the effect of diet on ischemic and hemorrhagic strokes separately. However, many of those studies have been too small to accurately assess the effects of diet on hemorrhagic stroke.

The latest study (TYN Tong et al, European Heart Journal, ehaa007, published February 24, 2020) is one of the largest studies to look at the effect of diet on both kinds of stroke. It has enough patients in the hemorrhagic group to get an accurate estimate of the effect of diet on hemorrhagic stroke.

How Was The Study Done?

This study analyzed data on diet and stroke from 418,329 participants in the EPIC (European Prospective Investigation into Cancer and Nutrition). Although the study has cancer in the title, it actually investigated the effect of nutrition on multiple diseases (Presumably, the study title was chosen because EPIC is a more appealing acronym than EPID (European Prospective Investigation into Diseases and Nutrition)).

The participants were recruited from 9 European countries (Denmark, Germany, Greece, Italy, the Netherlands, Norway, Spain, Sweden, and the UK). The average age of participants was 50, and they were followed for an average of 12.7 years.

At the beginning of the study participants completed country-specific dietary and lifestyle questionnaires.

The dietary assessment was a food frequency questionnaire that asked participants about their dietary intake for the year prior to enrollment in the study. The food frequency data were used to estimate daily intake of red meat, processed meat, poultry, fish, dairy products, eggs, grains, fruits, vegetables, legumes, nuts, seeds, and dietary fiber (It measured total fiber and fiber from grains, fruits and vegetables individually).

The outcome measured was the incidence of ischemic and hemorrhagic strokes during the 12.7-year follow-up.

Which Foods Affect Stroke Risk?

For ischemic stroke:

Each 200 gram/day increase in consumption of fruits and vegetables decreased ischemic stroke risk by 13% (200 grams roughly corresponds to one large apple or one large orange without the skin).

Each 10 gram/day increase in consumption of fiber decreased ischemic stroke risk by 23%. Most of this decreased stroke risk was due to fiber from whole grains, fruits, and vegetables.

- Each 4 gram/day increase in fiber from whole grains decreased ischemic stroke risk by 10%.

- Each 4 gram/day increase in fiber from fruits and vegetables decreased ischemic stroke risk by 12%.

Dairy foods decreased ischemic stroke risk with the following breakdown:

- Each cup of milk decreased ischemic stroke risk by 5%.

- Each half cup of yogurt decreased ischemic stroke risk by 9%.

- Each ounce of cheese decreased ischemic stroke risk by 12%.

Each 50 grams/day (2 ounces) of red meat increased ischemic stroke risk by 14%.

- However, red meat was only half as likely to increase risk of ischemic stroke when the diet was also rich in fruits, vegetables, whole grains, and legumes.

For hemorrhagic stroke:

Each 20 gram/day increase in consumption of eggs increased hemorrhagic stroke risk by 25% (20 grams roughly corresponds to about 1/2 of a small egg or 1/3 of a jumbo egg).

This study did not measure the effect of salt intake on hemorrhagic stroke risk.

No other foods measured in this study had a significant effect on hemorrhagic stroke risk.

However, hemorrhagic stroke is highly associated with high blood pressure. When we look at the influence of foods on high blood pressure, here are the Harvard School of Medicine recommendations for keeping blood pressure low:

Eat more fish, nuts and beans in place of high-fat meats.

Choose fruits and vegetables instead of sugary, salty snacks and desserts.

Select whole grains rather than refined grains.Eat fruit instead of drinking fruit juice.

Use unsaturated fats like olive, canola, soybean, peanut, corn or safflower oils instead of butter, coconut oil, or palm-kernel oil.

Use herbs, spices, vinegar, and other low-sodium flavorings instead of salt; Choose low-sodium foods whenever possible.

Why Is Diet And Stroke Risk So Confusing?

As I mentioned at the start of this article, part of the reason that the headlines about diet and stroke risk are so confusing is:

Many studies did not distinguish between the two types of stroke.

Other studies were too small to reliably estimate the effect of food on hemorrhagic stroke risk.

However, there are still some unexplained inconsistencies among recently published studies. It is these inconsistencies I would like to address. For example:

1) In a recent issue of Health Tips From the Professor I reported on a major study (500,000 people followed for 8.9 years) in China. That study came to the opposite conclusion about eggs and risk of hemorrhagic than the EPIC study I discussed above. It found:

People consuming one egg per day had a 26% decrease in hemorrhagic stroke risk and a 28% decrease in hemorrhagic stroke deaths compared to people who never or rarely consumed eggs.

In other words, the two studies came to opposite conclusions. In the China study eggs decreased risk of hemorrhagic stroke. In the European study (EPIC) eggs increased risk of hemorrhagic stroke. The reason for this discrepancy is not clear, but one can speculate it might be explained by differences in the underlying diets of the two countries:

In China the diet is primarily plant-based. The addition of an egg/day may provide needed protein, fat, and cholesterol (Some cholesterol is essential. We just overdo it in this country).

In Europe the diet is already high in protein, saturated fat, and cholesterol. Getting more of them from eggs may not be such a good thing.

In short, if your diet is primarily plant-based, the addition of an egg/day may be a good thing. However, if your diet is already high in meat, saturated fat, and cholesterol, the addition of an egg/day may not be a good thing.

2) In another recent issue of Health Tips From the Professor I reported on the EPIC-Oxford study that claimed vegetarians had 20% increased risk of hemorrhagic stroke compared to meat eaters.

Interestingly, the EPIC-Oxford study represented a very small portion (~10%) of the overall EPIC study and differed from the rest of the EPIC study in two important ways.

It looked at the effect of diets rather than foods on stroke risk.

Oxford was the only one of the 22 research centers involved in the EPIC study to invite people following a vegetarian diet to enroll in the study, so it had a much higher proportion of vegetarians than other centers that participated in the study.

The current study did not find any evidence that fruits, vegetables, nuts, seeds, beans, or whole grains influenced the risk of hemorrhagic stroke. In other words, in this much larger data set there was no evidence that the foods associated with a vegetarian diet increased hemorrhagic stroke risk.

However, most of the participants in larger EPIC study were also eating meats. They were not following a pure vegetarian diet.

As I said previously, “If the data on hemorrhagic stroke risk in the EPIC-Oxford study are true, it suggests it may not be a good idea to completely eliminate meat from our diet. However, you don’t need to add much meat to a vegetarian diet. The fish eaters in this study were consuming 1.4 ounces of fish per day. That was enough to eliminate the increased risk of hemorrhagic stroke.”

What Does This Mean For You?

For ischemic stroke (blockage of blood flow to the brain), which is the most common form of stroke, the data are clear cut:

Fruits, vegetables, whole grains and dairy foods are good for you. (Your mother was right.)

Red meat is not so good for you. However, the bad effect of red meat on ischemic stroke risk can be reduced by including plenty of fruits, vegetables, and whole grains in your diet.

These conclusions are consistent with multiple previous studies, and the mechanisms of these effects are well established.

For hemorrhagic stroke (bleeding from a weakened blood vessel in the brain) the data are not as clear cut.

If you are consuming a primarily plant-based diet, eggs appear to reduce your risk of hemorrhagic stroke.

If you are consuming a diet with lots of meat, saturated fat, and cholesterol, adding eggs may increase your risk of hemorrhagic stroke.

A vegetarian diet may increase your risk of hemorrhagic stroke. But you don’t need to add much meat to a vegetarian diet. Consuming 1.4 ounces of fish per day appears to be enough to eliminate the increased risk of hemorrhagic stroke.

The mechanisms of these effects of food on hemorrhagic stroke are unclear, so these conclusions may be modified by subsequent studies.

In terms of an overall take-home lesson on diet and stroke risk, my advice is: “A primarily plant-based diet is a good idea, but you don’t need to become a vegan purist. Nor do you want to follow fad diets that eliminate whole food groups. We have 5 food groups for a reason. Eliminating any of them may not be a good idea.”

The Bottom Line

A recent study examined the effect of various foods on the risk of the two major forms of stroke.

For ischemic stroke (blockage of blood flow to the brain), which is the most common form of stroke, the data are clear cut:

Fruits, vegetables, whole grains and dairy foods are good for you. (Your mother was right.)

Red meat is not so good for you. However, the bad effect of red meat on ischemic stroke risk can be reduced by including plenty of fruits, vegetables, and whole grains in your diet.

These conclusions are consistent with multiple previous studies, and the mechanisms of these effects are well established.

For hemorrhagic stroke (bleeding from a weakened blood vessel in the brain) the data are not as clear cut.

If you are consuming a primarily plant-based diet, eggs appear to reduce your risk of hemorrhagic stroke.

If you are consuming a diet with lots of meat, saturated fat, and cholesterol, adding eggs may increase your risk of hemorrhagic stroke.

A vegetarian diet may increase your risk of hemorrhagic stroke. But you don’t need to add much meat to a vegetarian diet. Consuming 1.4 ounces of fish per day appears to be enough to eliminate the increased risk of hemorrhagic stroke.

The mechanisms of these effects of food on hemorrhagic stroke are unclear, so these conclusions may be modified by subsequent studies.

For more details, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

Do Vegetarians Have A Higher Risk Of Stroke?

December 10, 2019 by Dr. Steve Chaney

What Are The Benefits And Risks Of A Vegetarian Diet?

Vegetarian diets are thought to be very healthy. Clinical studies show that vegetarian diets are associated with decreased risk of heart disease, diabetes, cancer, Alzheimer’s disease, and much more. What’s not to like?

That’s why the recent headlines claiming that vegetarian diets may increase the risk of stroke were so surprising. Advocates of meat-heavy diets like the Paleo and Keto diets were overjoyed. These results fit in with their view that we should be eating more meat protein and less plant protein. Nutrition experts, on the other hand, were asking: “What’s going on?” “How can this be?”

Those of you who are regular readers of “Health Tips From the Professor” know that I am an advocate of primarily plant-based diets. Thus, I felt a responsibility to analyze the study (TYN Tong et al, British Medical Journal, 366: 14897, 2019) behind the headlines impartially and give you, my readers, clear guidelines for the healthiest possible diet.

How Was The Study Done?

Let’s start with some background:

· A major study called the “European Prospective Investigation Into Cancer and Nutrition” (EPIC) has been underway since the early 90’s.

· The British component of this study is known as the EPIC-Oxford study.

· While the study has “cancer” in it’s title, it was designed to measure the impact of nutrition on many diseases. In this case, the study focused on heart disease and stroke.

· Finally, enrollment in the EPIC-Oxford study was designed to give a high proportion of vegetarians in the study population.

The EPIC-Oxford study enrolled 48,188 participants with no previous history of heart disease, stroke, or angina between 1993 and 2001. A detailed diet analysis was performed upon enrollment and again in 2010. Based on these data, the participants were divided into three groups:

1) Meat eaters (24,428 participants).

2) Fish eaters (7,506 participants). This group consumed fish but no other meats. People with this eating style are often called pescatarians.

3) Vegetarians (16, 254 participants). This group consumed dairy and eggs, but no meat. People with this eating style are often called lacto-ovo vegetarians.

4) The diet analysis also identified participants who were vegans (no animal foods). However, this group was too small to obtain statistically significant comparisons, so they were included with the lacto-ovo vegetarians in the vegetarian group.

Data on heart disease and stroke were obtained from the UK’s health service records through March 31st, 2016. The average time of follow-up for participants in the study was 18.1 years.

Without going into greater detail, this was a very large, well-designed study.

How Did The Diets Of The Three Groups Compare?

The first step in analyzing this study is to ask how the diets of the three groups compared.

Compared to meat eaters, the fish eaters consumed:

· No meat other than fish.

· Slightly less milk and significantly more cheese.

· Slightly more fruits & vegetables.

· Significantly more legumes & soy foods, nuts & nut butter.

· Slightly more carbohydrate and slightly less protein.

· Slightly less saturated fat and slightly more polyunsaturated fat.

· Around 260 fewer calories per day.

Compared to fish eaters, the vegetarians consumed:

· No meat.

· Slightly less milk & cheese.

· About the same amount of fruits & vegetables.

· Significantly more legumes & soy foods, nuts & nut butter.

· Slightly more carbohydrate and slightly less protein.

· About the same saturated and polyunsaturated fat.

· Around 125 fewer calories per day.

On average, the vegetarians consumed about 1 cup of milk and one ounce of cheese per day. The fish eaters consumed 1.4 ounces of fish per day.

In terms of comparisons:

· The biggest differences were between the fish eaters and the meat eaters. It would be fair to say that the fish eaters consumed a primarily plant-based diet with added fish and dairy.

· The biggest differences between the vegetarians and fish eaters was that the fish eaters got a significant percentage of their protein from fish, while the vegetarians got a significant amount of their protein from plant sources. Otherwise, their diets were fairly comparable.

Finally, the 10-year follow-up diet analysis showed that most participants stuck with their initial diet.

Do Vegetarians Have A Higher Risk Of Stroke?

Now, for the study results:

· Compared to meat eaters, fish eaters had 13% lower risk of heart disease, and vegetarians had a 22% lower risk of heart disease.

o For vegetarians this corresponds to 10 fewer cases of heart disease per 1,000 people over 10 years.

· Compared to meat eaters, vegetarians had a 20% higher risk of stroke, mostly due to an increased risk for hemorrhagic stroke.

o For vegetarians this corresponds to 3 additional cases of stroke per 1,000 people over 10 years.

· The risk of stroke was essentially identical for fish eaters and meat eaters.

In many other aspects, vegetarians were healthier than meat-eaters. For example, they:

· Weighed less.

· Had lower blood pressure.

· Had lower total and LDL cholesterol.

· Were less likely to have developed diabetes during the study.

· Were less likely to have required long-term treatment for other illnesses.

What Are The Strengths And Weaknesses Of The Study?

The strength of this study is obvious. It was a very large, well-designed study. The study also lasted a long time. Participants in the study were followed for almost 20 years.

There are two clear weaknesses, however:

1) Numerous previous studies have confirmed that vegetarian diets decrease heart disease risk by about 20%. However, none of those previous studies have reported an increase in stroke risk. This study is an outlier.

2) There is no clear mechanism that explains why a vegetarian diet might increase stroke risk. Based on previous observations that statin drugs increase the risk of hemorrhagic stroke, the authors suggested the increased stroke risk might be due to lowered LDL cholesterol levels.

This mechanism is speculative at present. Furthermore, if true, it would suggest that any intervention (drug or nutritional) that lowers LDL cholesterol would increase stroke risk.

In the words of the authors:

· “The present study has shown that British adults who were fish eaters or vegetarians had lower risks of heart disease than meat eaters, but that vegetarians had higher risks of stroke.

· Future work should include further measurements…to identify which factors may cause the observed associations. [In plain English: We need to understand how vegetarian diets might increase stroke risk before we put too much weight on the results of this study.]

· Additional studies in other large-scale cohorts with a high proportion of non-meat eaters are needed to confirm the generalizability of these results and assess their relevance for clinical practice and general health.” [In plain English: More studies are needed to confirm this observation before we start changing our recommendations about what constitutes a healthy diet.]

What Are The Benefits And Risks Of A Vegetarian Diet?

Let’s assume for a minute that the results of this study are accurate and take a closer look at the benefits and risks of a vegetarian diet. Here is my assessment:

1) This report is troubling, but it may not be correct. The association of vegetarian diets with a slight increase in stroke risk has only been seen in a single study. This study needs to be confirmed before we become too concerned about vegetarianism increasing stroke risk.

2) On the balance, vegetarian diets should still be considered very healthy. They lower the risk of heart disease, high blood pressure, diabetes, some cancers, inflammatory diseases and possibly even Alzheimer’s disease.

3) However, I have often said that we have 5 food groups for a reason, and it is not a good idea to eliminate whole food groups. In the past, I have used that statement to critique diets that leave out important plant food groups like fruit, whole grains, and legumes.

If the data on stroke risk in this study are true, it suggests it might also not be a good idea to leave out meat. However, you don’t need a lot of meat. The fish eaters in this study were consuming 1.4 ounces of fish per day. That was enough to eliminate the increased risk of stroke.

4) In addition, you don’t have to be a vegan purist to enjoy the health benefits of a primarily plant-based diet. As I describe in my book, “Slaying The Food Myths”, primarily plant-based diets ranging from vegan through pescatarian and semi-vegetarian to Mediterranean and DASH are all incredibly healthy.

I personally follow a semi-vegetarian diet but often recommend Mediterranean and DASH diets to others because they are the easiest primarily plant-based diets for the average American to follow.

5) Finally, if you have a family history, or are at high risk, of stroke, I recommend prudence until we know more. You may wish to adopt a version of primarily plant-based diets that incorporates some meat (That would be in the pescatarian to DASH range of primarily plant-based diets). Your heart will thank you, and you won’t increase your risk of stroke.

The Bottom Line

A recent study enrolled 48,188 British adults; divided them into meat eaters, fish eaters, and vegetarians; followed them for 18.1 years; and looked at their risk for heart disease and stroke. The results were:

· Compared to meat eaters, fish eaters had 13% lower risk of heart disease, and vegetarians had a 22% lower risk of heart disease.

o For vegetarians this corresponds to 10 fewer cases of heart disease per 1,000 people over 10 years.

· Compared to meat eaters, vegetarians had a 20% higher risk of stroke, mostly due to an increased risk for hemorrhagic stroke.

o For vegetarians this corresponds to 3 additional cases of stroke per 1,000 people over 10 years.

· The risk of stroke was essentially identical for fish eaters and meat eaters.

Here is my perspective:

4) In addition, you don’t have to be a vegan purist to enjoy the health benefits of a primarily plant-based diet. As I describe in my book, “Slaying The Food Myths” (https://slayingthefoodmyths.com), primarily plant-based diets ranging from vegan through pescatarian (the fish eaters in this study) and semi-vegetarian to Mediterranean and DASH are all incredibly healthy.

I personally follow a semi-vegetarian diet but often recommend Mediterranean and DASH diets to others because they are the easiest primarily plant-based diets for the average American to follow.

For more details on the study and what it means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.